Return-Path: <majordom@post.thorcom.com> Received: (qmail 28800 invoked from network); 17 Jan 2000 12:22:59 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 17 Jan 2000 12:22:59 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12AB1F-0007En-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 17 Jan 2000 12:12:25 +0000 Received: from mailhost.netscapeonline.co.uk ([194.200.20.13]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12AB1D-0007Ei-00 for rsgb_lf_group@blacksheep.org; Mon, 17 Jan 2000 12:12:24 +0000 Received: from [195.44.220.178] (helo=netscapeonline.co.uk) by mailhost.netscapeonline.co.uk with esmtp (Exim 3.02 #1) id 12AB19-0001xF-00 for rsgb_lf_group@blacksheep.org; Mon, 17 Jan 2000 12:12:19 +0000 Message-ID: <38837377.985BD716@netscapeonline.co.uk> X-Priority: 3 X-MSMail-Priority: Normal Date: Mon, 17 Jan 2000 11:54:31 -0800 From: "g3kev" <g3kev@netscapeonline.co.uk> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Organization: Netscape Online member X-Mailer: Mozilla 4.6 [en-gb]C-CCK-MCD NetscapeOnline.co.uk (Win95; I) X-Accept-Language: en-GB,en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Re: Transatlantic References: <388286AC.2ACD0DEE@netscapeonline.co.uk> <02ed01bf605e$2d643f00$0600a8c0@main> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: <majordom@post.thorcom.com> Dave wrote: > Dear all, > > Assuming that we're sticking to 1W erp then what does it matter how big the > antenna is as long as the power is sufficient to give the required erp? There is a big difference in the radiation pattern and angle of take off between a high vertical antenna and a very low antenna given the same rf power to the antenna. 1 Watt erp from a dummy load or low horizontal wire is hardly the same as 1 Watt erp from a vertical antenna at 120 ft. There is also the RX consideration especially on long haul signals. At LF the delivery system ie ANTENNA is the most important factor. Even with large towers, and high elaborate antennas, which are still physically small relative to 137 khz and a limit of 1W erp, one has to realize the limitations, but at least there might be a chance. 73 de Mal/G3KEV > > CFH peaks 33dB above the noise regularly (in 100Hz filter). If its erp is > around 8kW as rumoured then a 4W erp signal would be on the noise level, > normal good copy, and a 1W signal would be 6dB down. No problem for > Spectrogram. > > There is a VE station building for the band and he intends to try some tests > next "fall" from VO1. That should do it! > > 73 de G3YXM.